A new species of Lepiota from China

In this report we describe the three species in Lepiota sect. Lepiota occurring in tropical China. Lepiota attenuata is a new species and is characterized by a pileus with brownish yellow squamules and radially sulcate striate margin, penguin-shaped spores that are distinctively narrowed toward the apex and inflated submoniliform or catenulate elements in the pileus covering. We compared the type specimens of L. metulispora and L. thrombophora with tropical Chinese specimens; both taxa occur in the study area. Phylogenetic relationships among the tropical Chinese species and other closely related species in the genus were inferred based on DNA sequences of the nuclear ribosomal genes (ITS, LSU and IGS) and the mitochondrial small ribosomal RNA gene (mtSSU).     

中国环柄菇属一新种

发表中国环柄菇属一新种 ,即红鳞环柄菇 (LepiotasquamulosaB .TolgoretY .Li) ,模式标本存放在吉林农业大学菌物标本馆 (HMJAU)。     

Synthesis of analogues of amaninamide, an amatoxin from the white Amanita virosa mushroom

Analogs of amaninamide, due to the absence of a 6-hydroxy group in the tryptophan moiety, are more easily accessible by synthesis than derivatives of alpha-amanitin. Syntheses of bicyclic octapeptide thioethers 1f-1m have been carried out starting from linear Hpi-S-trityl-octapeptides (3), cyclization by intramolecular 2'-indolylthioether formation yielding monocyclic peptides (2) and final cyclization by DCCI. One of the bicyclic thioethers was oxidized to yield the corresponding chromatographically separated (R)- and (S)-sulfoxides, respectively. The products were characterized by RF-values, u.v. and CD spectra as well as by mass (FAB) spectroscopy. The widely differing inhibitory activities on RNA polymerase II (or B) from calf thymus are listed.     

Accidental fatal poisoning with ethyl fluoroacetate]

Fluoroacetic salts belong to the most toxic chemicals. They are used for various purposes, and form stable compounds in some plants. A case of poisoning with ethyl fluoroacetate is presented in detail. Diagnostic problems and therapy which failed due to the late diagnosis and dramatic progress in the symptoms of poisoning are also discussed. Fluoroacetic ion alone is non-toxic but in vivo forms fluorotricarboxylic acid, which blocks cellular metabolism at the citrate stage. Symptoms occur with a delay but lethal synthesis of fluorotricarboxylic acid leads to the irreversible cellular dysfunction, especially in CNS and circulatory system. Poisoning may be treated with monoacetin and acetamide. An emphasis is on health hazards resulting from the exposure to fluoroacetate and necessity to observe strictly safety regulations.     

S-deoxo-Abu1,Ile3-amaninamide, an inactive amatoxin analogue

The title compound 3, an amatoxin analogue containing L-alpha-aminobutyric acid instead of L-asparagine in position 1, as in natural toad stool peptides, has been synthesized. It does not inhibit the eukaryotic DNA-dependent RNA polymerase form II (or B) in concentrations up to 10(-4)M, whereas 50% inhibition is exerted in 10(-6)M solution by the corresponding Asn-analogue S-deoxo-Ile3-amaninamide 2. The striking difference seems to be due to a relatively small variation of the conformation recognized by sensitive NMR spectroscopic methods.     

Isolation of an amatoxin binding protein (ABP) different from RNA-polymerase B and C ((author's transl))]

During the isolation of the amatoxin RNA-polymerase B-complex from calf thymus tissue we also isolated a protein (ABP) which shows such strong affinity to [3H)amanin that significant binding occurs at low concentrations (10-7M) of the label. The presence of a new amatoxin-complex is demonstrated by coprecipitation of amatoxin and ABP with ammonium sulphate and the common chromatography on phosphocellulose and Sephadex G-25. The new protein ABP is characterized by denaturating sodium dodecylsulphate-gel electrophoresis. The molecular masses of both main bands - possibly subunits of ABP - are determined as 100000 and 10000 - 15000 Dalton and different from the subunit pattern of RNA-polymerases B and C.     

Two New Records of Genus Lepiota (Agaricaceae) from Pakistan

Biology Bulletin - In our ongoing efforts to inventory the lepiotaceous fungi of Pakistan, we here report on two species, new to Pakistan: Lepiota cingulum is also new to Asia, and L. oreadiformis....     

Metabolites of 2-aminophenol from fruit bodies of Lepiota americana (Agaricales)

From the acetone extract of the North American toadstool Lepiota americana 2-aminophenoxazin-3-one (1) and a novel amino-1,4-benzoquinone derivative, lepiotaquinone (2), were isolated. The structure of 2 was confirmed by its preparation from 2-aminophenol and amino-1,4-benzoquinone.     

Description and affinities of a sequestrate Lepiota (Agaricaceae) from Australia

The novel Australian sequestrate species Lepiota geogenia is described and illustrated. It is characterized by globose to subglobose sporocarps that stain pale yellow with handling, and fusiform, asymmetric spores. Lepiota geogenia is a member of sect. Lepiota, to which the sequestrate western American Cryptolepiota spp, Lepiota viridigleba, and the European slightly secotioid L. sardoa also belong. We place the Cryptolepiota species within Lepiota, and provide two new names and one new combination.     

A case of mushroom poisoning from Suillus luteus

Suillus luteus, although often eaten, can cause illness. We describe the sickness and suggest removal of the cuticle before eating.